U.S. patent number 9,625,653 [Application Number 15/212,127] was granted by the patent office on 2017-04-18 for universal fiber optic connector.
This patent grant is currently assigned to IPG PHOTONICS CORPORATION. The grantee listed for this patent is IPG Photonics Corporation. Invention is credited to Mark W. Byer, Gregory L. Keaton, Manuel J. Leonardo.
United States Patent |
9,625,653 |
Byer , et al. |
April 18, 2017 |
Universal fiber optic connector
Abstract
A universal fiber optic connector includes a housing and a fiber
attachment element configured to attach an optical fiber in the
housing. The attachment element positions the optical fiber such
that an end face of the fiber is held within the housing. The fiber
end face is positioned such that a beam of light emerging from the
fiber end face has a defined wavefront located at a specified
interface.
Inventors: |
Byer; Mark W. (Mountain View,
CA), Leonardo; Manuel J. (San Francisco, CA), Keaton;
Gregory L. (San Francisco, CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
IPG Photonics Corporation |
Oxford |
MA |
US |
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Assignee: |
IPG PHOTONICS CORPORATION
(Oxford, MA)
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Family
ID: |
51581071 |
Appl.
No.: |
15/212,127 |
Filed: |
July 15, 2016 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20160327753 A1 |
Nov 10, 2016 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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14850788 |
Sep 10, 2015 |
9395496 |
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PCT/US2014/026686 |
Mar 13, 2014 |
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61782715 |
Mar 14, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02B
6/32 (20130101); G02B 6/3817 (20130101); G02B
6/3809 (20130101); G02B 6/3628 (20130101) |
Current International
Class: |
G02B
6/38 (20060101); G02B 6/32 (20060101); G02B
6/36 (20060101) |
Field of
Search: |
;385/70,58 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
International Search Report and Written Opinion for International
Application No. PCT/US2014/026686, dated Jul. 14, 2014. cited by
applicant .
Non-Final Office Action for U.S. Appl. No. 14/850,788, dated Dec.
14, 2015. cited by applicant .
Notice of Allowance for U.S. Appl. No. 14/850,788, dated Mar. 28,
2016. cited by applicant .
U.S. Appl. No. 61/782,715, to Mark W. Byer, filed Mar. 13, 2014.
cited by applicant .
U.S. Appl. No. PCT/US2014/026686, to Mark W. Byer, filed Mar. 13,
2014. cited by applicant.
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Primary Examiner: Blevins; Jerry
Attorney, Agent or Firm: Isenberg; Joshua D. JDI Patent
Parent Case Text
CLAIM OF PRIORITY
This application is a continuation of commonly-assigned, co-pending
U.S. patent application Ser. No. 14/850,788, filed Sep. 10, 2015,
the entire disclosure of which is incorporated herein by reference.
U.S. patent application Ser. No. 14/850,788 is a continuation of
International Application Number PCT/US14/26686, filed Mar. 13,
2014, the entire disclosure of which is incorporated herein by
reference. International Application Number PCT/US14/26686 claims
the priority benefit of commonly-assigned, U.S. Provisional Patent
Application No. 61/782,715, filed Mar. 14, 2013, the entire
disclosure of which is incorporated herein by reference.
Claims
The invention claimed is:
1. A universal fiber optic connector, comprising: a housing; a
fiber attachment element configured to attach an optical fiber in
the housing, wherein the attachment element positions the optical
fiber such that an end face of the fiber is held within the
housing, wherein the fiber end face is positioned such that a beam
of light emerging from the fiber end face has a defined wavefront
located at a specified interface, wherein a radius of the defined
wavefront is large enough that any uncontrolled lateral offset
between the housing and a housing of a second similarly configured
universal fiber optic connector does not diminish the power
transmitted by more than about 10%, when the universal fiber optic
connector and the similarly configured universal fiber optic
connector are connected.
2. The connector of claim 1, further comprising one or more optics,
wherein the beam is transmitted through the one or more optics so
that it achieves the defined wavefront at the specified interface,
wherein the housing is designed so that any light that is not
coupled into the fiber is controlled, either through scattering,
absorption or complete transmission.
3. The connector of claim 2, wherein the attachment element retains
the fiber end in a fixed position with respect to the optics.
4. The connector of claim 3, wherein the position of the fiber end
is configured such that the fiber end is centered with respect to
an optical axis of the optics and an axis of a light beam emerging
from the fiber end is angularly aligned with respect to the optical
axis of the optics.
5. The connector of claim 4, wherein the position of the fiber end
and the properties of the optics are selected such that light
emerging from the fiber end has the defined wavefront at the
specified interface.
6. The connector of claim 1, wherein the defined wavefront may be
defined in terms of beam spot size and divergence angle at the
specified interface.
7. The connector of claim 1, wherein the attachment element is a
sleeve and adhesive, a glass capillary and adhesive, a metal sleeve
or a mechanical fastener.
8. The connector of claim 1, wherein the housing is of transparent
(at given wavelength) or opaque materials.
9. The connector of claim 1, wherein the housing is made of metal,
glass or ceramic.
10. The connector of claim 1, wherein the defined wavefront is
collimated.
11. The connector of claim 1, further comprising an electrical
connector configured to transmit electrical current or signals to a
similarly configured universal fiber optic connector when the
universal fiber optic connector is coupled to the similarly fiber
optic connector.
12. A universal fiber optic connector, comprising: a housing; a
fiber attachment element configured to attach an optical fiber in
the housing, wherein the attachment element positions the optical
fiber such that an end face of the fiber is held within the
housing, wherein the fiber end face is positioned such that a beam
of light emerging from the fiber end face has a defined wavefront
located at a specified interface, wherein a divergence half-angle
of the defined wavefront is small enough that any uncontrolled
lateral offset between the housing and a housing of a second
similarly configured universal fiber optic connector does not
diminish the power transmitted by more than about 10% when the
universal fiber optic connector and the similarly configured
universal fiber optic connector are connected.
13. The connector of claim 12, wherein a divergence half-angle of
the defined wavefront is sufficiently larger than an angular
alignment tolerance between the housing and a housing of a second
similarly configured universal fiber optic connector such that
optical power transmitted between the universal fiber optic
connector and the similarly configured fiber optic connector is not
diminished by more than about 10% when the universal fiber optic
connector and the similarly configured universal fiber optic
connector are connected.
14. A universal fiber optic connector, comprising: a housing; a
fiber attachment element configured to attach an optical fiber in
the housing, wherein the attachment element positions the optical
fiber such that an end face of the fiber is held within the
housing, wherein the fiber end face is positioned such that a beam
of light emerging from the fiber end face has a defined wavefront
located at a specified interface , wherein a divergence half-angle
of the defined wavefront is sufficiently larger than an angular
alignment tolerance between the housing and a housing of a second
similarly configured universal fiber optic connector such that
optical power transmitted between the universal fiber optic
connector and the similarly configured fiber optic connector is not
diminished by more than about 10% when the universal fiber optic
connector and the similarly configured universal fiber optic
connector are connected.
15. A universal fiber optic connector, comprising: a housing; a
fiber attachment element configured to attach an optical fiber in
the housing, wherein the attachment element positions the optical
fiber such that an end face of the fiber is held within the
housing, wherein the fiber end face is positioned such that a beam
of light emerging from the fiber end face has a defined wavefront
located at a specified interface; and an alignment body configured
to constrain degrees of freedom of the housing substantially
parallel to a plane of the specified interface.
16. The connector of claim 15, wherein the alignment body permits
motion in a direction substantially perpendicular to the plane of
the specified interface.
17. The connector of claim 16, wherein the alignment body is a
tube.
Description
FIELD OF THE DISCLOSURE
The present disclosure relates to fiber optic systems, and in
particular, to connectors for high power optical fibers having
different beam sizes.
BACKGROUND
When trying to build fiber laser systems (including fiber
amplifiers connected to their pump and seed sources), we have been
frustrated by the lack of quick, snap-together connectors for high
power fibers.
For example, although the SMA connector is suitable for high-power,
multimode fiber (typical core diameters of 100 .mu.m to 400 .mu.m),
it cannot be used for single mode fiber (typical mode diameters of
6 .mu.m to 30 .mu.m), because the SMA connector cannot provide the
tolerance required to align to such a small spot.
One connector that can be used for single mode fibers is the FC/PC
connector. However, this connector was designed for low powers,
such as are used in telecommunications. The FC/PC connector cannot
reliably be used above one Watt of power.
Another problem with the standard connectors is that they cannot
connect fibers of different mode sizes. For example, the output of
a single-mode fiber laser with a mode diameter of 6 .mu.m cannot be
connected to a large mode area fiber with a mode area of 30
.mu.m.
SUMMARY
According to aspects of the present disclosure, a universal fiber
optic connector includes a housing and a fiber attachment element
configured to attach an optical fiber in the housing. The
attachment element positions the optical fiber such that an end
face of the fiber is held within the housing. The fiber end face is
positioned such that a beam of light emerging from the fiber end
face has a defined wavefront located at a specified interface.
In some implementations, the connector further includes one or more
optics, wherein the beam is transmitted through the one or more
optics so that it achieves the defined wavefront at the specified
interface. In such implementations, the connector the attachment
element can be configured to retain the fiber end in a fixed
position with respect to the optics. For example, the position of
the fiber end may be configured such that the fiber end is centered
with respect to an optical axis of the optics and an axis of a
light beam emerging from the fiber end is angularly aligned with
respect to the optical axis of the optics. When the fiber end is so
configured the position of the fiber end and the properties of the
optics can be selected such that light emerging from the fiber end
has the defined wavefront at the specified interface.
The defined wavefront may be defined in terms of beam spot size and
divergence angle at the specified interface.
In some implementations, the housing is designed so that any light
that is not coupled into the fiber is controlled, either through
scattering, absorption or complete transmission.
There are a number of possible configurations for the attachment
element. For example, the attachment element may be a sleeve and
adhesive, a glass capillary an adhesive, a metal sleeve or a
mechanical fastener.
There are a number of different possible configurations for the
housing. For example, the housing can be made of materials that are
transparent at a given wavelength or opaque.
Some specific examples of materials for the housing include metal,
glass or ceramic.
There are a number of different possible configurations for the
defined wavefront. For example, in some implementations, the
defined wavefront can be a circular Gaussian beam at its waist. In
certain such implementations, a radius of the defined wavefront is
large enough that any uncontrolled lateral offset between two the
housing and a housing of a second similarly configured universal
fiber optic connector does not diminish the power transmitted by
more than about 10%, when the universal fiber optic connector and
the similarly configured universal fiber optic connector are
connected.
In certain implementations, the defined wavefront is
collimated.
In one possible implementation, the connector further includes an
alignment body configured to constrain degrees of freedom of the
housing substantially parallel to a plane of the specified
interface. The alignment body may also permit motion in a direction
substantially perpendicular to the plane of the specified
interface. One example of such an alignment body is a tube.
In certain implementations, the connector further includes an
electrical connector configured to transmit electrical current or
signals to a similarly configured universal fiber optic connector
when the universal fiber optic connector is coupled to the
similarly fiber optic connector.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional schematic diagram of a universal fiber
optic connector according to an aspect of the present
disclosure.
In FIG. 2, a first universal fiber optic connector is shown aligned
or connected to a second universal fiber optic connector such that
light from a first fiber can be coupled into a second fiber and
vice-versa.
FIG. 3 shows one possible alignment/attachment scheme between two
universal fiber optic connectors.
FIG. 4 shows another possible alignment/attachment scheme between
two universal fiber optic connectors.
FIG. 5 shows another possible alignment/attachment scheme between
two universal fiber optic connectors.
DETAILED DESCRIPTION
Aspects of the present disclosure are directed to fiber optic
connectors that can handle high powers and can couple fibers of
different mode sizes. The connectors are easily uncoupled and
recoupled.
A. Coupling Single Mode Fibers
Each fiber end that is to be connectorized may be fitted with a
connection box, referred to herein as a "C-box". The C-box includes
optics that relay light from the fiber end to a coupling face of
the connection box. The optics of the connection box shape the
light beam emitted from the fiber to produce a standard spot size
and divergence angle at the coupling face. This standard beam shape
is called the "defined wavefront."
By symmetry, the connection box also works in reverse: a light beam
that is incident upon the coupling face will be relayed into the
fiber, as long as the incident beam has the defined wavefront
configuration at the coupling face. This means that when two
connection boxes are joined together at their coupling faces, light
is relayed between the two corresponding fibers. This works even if
the two fibers have different mode sizes.
Fibers of different mode sizes require connection boxes that have
different optics inside. Each connection box is designed so that
light emitted from its corresponding fiber produces a defined
wavefront. Then any two fibers can be connected via connection
boxes, since the common interface is the defined wavefront.
B. Defined Wavefront.
By way of example, and not by way of limitation, the defined
wavefront may be a circular Gaussian beam at its waist. The radius
of the defined wavefront is preferably large enough that any
uncontrolled lateral offset between two connection boxes does not
appreciably diminish the power transmitted. For example, suppose
that two connection boxes can be removably attached with a lateral
offset of .+-.25 .mu.m from perfect alignment. In such a case, the
defined wavefront waist radius w.sub.0 (defined by the 1/e.sup.2
point of the intensity) should be at least three times this offset,
or 75 .mu.m, to guarantee that at least 90% of the power is
transmitted when the connection boxes are coupled.
On the other hand, there is also a maximum size for the universal
wavefront, since the coupling between two connection boxes becomes
too sensitive to angular misalignment between the boxes when the
universal wavefront diameter gets too large. Typically, the
connection boxes can be aligned with an angle tolerance of .+-.25
.mu.rad. To guarantee at least 90% power transmission, the
divergence half-angle of the universal wavefront should be at least
three times the angle tolerance, or 75 .mu.rad. The divergence
half-angle .theta..sub.d can be expressed in terms of the
wavelength .lamda. of the light and the mode radius w.sub.0 as:
.theta..sub.d=.lamda./(.pi.w.sub.0) (1) Therefore, to maintain a
divergence angle of 75 .mu.rad or more, the mode radius must be
less than 4.2 mm.
Therefore, the mode radius of the defined wavefront is preferably
between 75 .mu.m and 4.2 mm. To balance the angle tolerance and the
lateral offset tolerance, the radius can be the geometric mean
between the minimum and maximum sizes. The result is a mode radius
of 560 .mu.m.
C. Examples of C-Box Construction
FIG. 1 shows basic construction of a C-Box 11. A fiber 1 is
attached by an attachment element 2 in a housing 3. The attachment
element 2 may be a sleeve and adhesive, a glass capillary and
adhesive, a metal sleeve and mechanical fastener, etc. The housing
3 may be of transparent (at given wavelength) or opaque materials.
Either metal, glass or ceramic are the preferred materials for the
housing 3. The attachment element 2 positions the fiber such that
an end face 4 of the fiber 1 is held within the housing 3 so that
it does not move with respect to a defined wavefront 9 located at a
specified interface 8. A beam of light 5 emerging from the fiber
end face 4 propagates along an axis substantially parallel to the
fiber axis. The beam 5 may be transmitted through one or more
optics 6 and 7 so that it achieves the defined wavefront 9 at the
specified interface 8. The housing 3 may be designed so that any
light 10 that is not coupled into the fiber is controlled, either
through scattering, absorption or complete transmission.
The attachment element 2 may retain the fiber 1 such that its end 4
is in a fixed position with respect to the optics 6, 7. The
position of the fiber end 4 may be configured such that the fiber
end is centered with respect to an optical axis of the optics 6, 7
and an axis of the beam 5 emerging from the fiber end 4 is
angularly aligned with respect to the optical axis of the optics 6,
7. The position of the fiber end 4 and the properties of the optics
6, 7 are selected such that light emerging from the fiber end has
the defined wavefront 9 at the specified interface 8. The defined
wavefront 9 may be defined in terms of beam spot size and
divergence angle at the specified interface.
In FIG. 2, a first C-box 21 is shown aligned or connected to a
second C-box 22 such that the light from a first fiber 1A is
coupled into a second fiber 1B and vice-versa. The C-boxes 21 and
22 include optics 6 that are configured such that light emerging
from fibers 1A and 1B has a defined wavefront 9 at a defined
interface plane 8. For simplicity, a single optic 6 is shown for
each C-box. Alternatively, each C-box may contain multiple optics,
e.g., as shown in FIG. 1. Because of the defined wavefront 9 at the
defined interface plane 8, the two fibers 1A, 1B may be of
different Numerical Apertures or diameters.
FIG. 3 shows one possible alignment/attachment scheme between two
C-boxes. A first C-Box 21 is aligned with respect to the second
C-box 22 such that each both defined wavefronts 9 overlap at the
defined interface plane 8. In FIG. 3, an external alignment body 13
is used as the master reference. This alignment body may be a
v-groove, dovetail, pins or some other means by which to constrain
the degrees of freedom substantially parallel to the defined
interface plane 8. This permits motion in a direction substantially
perpendicular to the defined interface plane 8. If the defined
wavefront 9 is collimated, the two C-Boxes 21, 22 would not have to
touch in order to transmit light between the coupled fibers.
FIG. 4 shows another possible alignment/attachment scheme between
two C-boxes. The first C-Box 21 is aligned with respect to the
second C-box 22 such that both C-boxes have defined wavefronts 9
that overlap at the defined interface plane 8. In FIG. 4, an
external alignment body 13 is used as the master reference. In the
example shown in FIG. 4, the alignment body 13 is a critically
aligned tube or exterior coupling body. By way of example, and not
by way of limitation, glass tubes can be made to exacting
tolerances and would provide adequate tolerances. Metal tubes may
be used to contain stray uncoupled light. The external alignment
body 13 provides means by which to constrain the degrees of freedom
substantially parallel to the defined interface plane 8. This
permits motion in a direction substantially perpendicular to the
defined interface plane. If the defined wavefront 9 is collimated,
the two C-Boxes 21, 22 would not have to touch in order to transmit
light between the coupled fibers.
FIG. 5 shows another possible alignment/attachment scheme between
two C-boxes 21, 22. The first C-Box 21 is aligned with respect to
the second C-box 22 such that each both defined wavefronts 9
overlap at the defined interface plane 8. In FIG. 5, the two
C-Boxes 21, 22 are aligned and coupled together by some coupling
mechanism 15 such that appropriate tolerances are achieved. For
one-time alignments, the coupling mechanism 15 may be mechanically
aligned and then affixed with an adhesive or welded in place (etc).
For purposes of decoupling, the coupling mechanism 15 may include
precision machined features, etched features, micromachined,
precision pins, etc. The coupling mechanism maintains sufficiently
tight repeatable tolerances substantially perpendicular to the
coupling plane 8 such that adequate light coupling between the
fibers 1A and 1B is achieved.
Additionally, FIG. 5 shows a mechanism by which electrical signals
may also be transmitted. A wire or wires 17 may be secured to the
C-Boxes with a connector 16 such that when the first C-box 21 and
second C-box 22 are connected, electrical signals or current may
pass. Such a connection would enable communication of interlock
status or other signals and/or optical monitoring information.
While the above is a complete description of the preferred
embodiment of the present invention, it is possible to use various
alternatives, modifications and equivalents. Therefore, the scope
of the present invention should be determined not with reference to
the above description but should, instead, be determined with
reference to the appended claims, along with their full scope of
equivalents. Any feature described herein, whether preferred or
not, may be combined with any other feature described herein,
whether preferred or not. In the claims that follow, the indefinite
article "A", or "An" refers to a quantity of one or more of the
item following the article, except where expressly stated
otherwise. The appended claims are not to be interpreted as
including means-plus-function limitations, unless such a limitation
is explicitly recited in a given claim using the phrase "means
for."
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